Dishwasher

ABSTRACT

A dishwasher includes a tub defining a washing chamber, a door for opening/closing the tub, a condenser provided inside the door to condense steam discharged from the tub, a fan assembly connected to the condenser, and an outside air guide for supplying outside air to the fan assembly. The fan assembly includes a discharge opening through which steam from inside the tub is discharged into the condenser.

This application claim the benefit of Korean Patent Application No.10-2006-0100609, filed on Oct. 17, 2006, which is hereby incorporated byreference for all fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dishwasher, and more particularly, toa dryer of a dishwasher, which can rapidly condense steam generatedduring a drying cycle.

2. Description of the Related Art

A dishwasher is a machine that sprays wash liquid through spray nozzlesunder high pressure to remove food or residue left on dishes, or anyitems in the dishwasher.

The dishwasher includes a tub defining a washing chamber and a sumpmounted on a bottom of the tub to contain the wash liquid. A washingpump is installed inside the sump to pump the wash liquid to the spraynozzles. The wash liquid is sprayed under high pressure through sprayholes formed at the ends of the spray nozzles. The wash liquid, sprayedunder high pressure, collides against the surfaces of the dishes, sothat food residue and impurities on the dishes fall down to the bottomof the tub.

High-temperature steam can be applied in a dishwasher using aventilation-type drying method or a circulation-type drying method.

According to the ventilation-type drying method, a drying fan dischargesmoist air out of the tub. However, a dishwasher using theventilation-type drying method has a drawback in that high-temperature,high-humidity air is directly discharged out of the tub causingdiscomfort to a user near the dishwasher. Also, due to the directdischarge of the high-temperature, high-humidity air, the user or childmay get scalded by the discharge.

During the discharge of the high-temperature, high-humidity air, steammay be condensed around a steam outlet and flow to the floor causing thefloor to become wet. Further, there is a danger that a user may slide orfall down onto the floor due to the condensed water collecting on thefloor. Moreover, mildew may form from the condensed water collected onthe floor.

According to the circulation-type drying method, steam is condensed by acondenser provided inside the tub and is again introduced into the tub.A dishwasher using the circulation-type drying method has a drawback inthat steam is not condensed sufficiently or efficiently because thecondenser is small in size. Due to the small-sized condenser, it takes along time to dry the dishes and an additional condenser may be required.

SUMMARY

Accordingly, a dishwasher that substantially obviates one or more of theaforementioned problems due to limitations and disadvantages of therelated art is highly desirable.

An object of the present invention is to provide a dishwasher having animproved condenser that rapidly condenses steam.

Another object of the present invention is to provide a dishwasher thatshortens a drying time by rapidly condensing steam discharged during adry cycle.

A further object of the present invention is to provide a dishwasherthat rapidly condenses steam, so that a user does not feel uncomfortableor get scalded by the discharge of the dishwasher.

A still further object of the present invention is to provide adishwasher that has an improved condenser, so that additional condensersare not required.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and the claims, as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein,there is provided a dishwasher including a tub defining a washingchamber; a door for opening/closing the tub; a condenser provided insidethe door to condense steam discharged from the tub; a fan assemblyconnected to the condenser, the fan assembly including a discharge holethrough which steam inside the tub is discharged to the condenser; andan outside air guide for supplying outside air to the fan assembly.

According to another aspect of the present invention, there is provideda dishwasher including a tub; a door for opening/closing a front side ofthe tub, the door including a door cover defining an exterior portion ofthe dishwasher and a door liner connected to a rear surface of the doorcover; a condenser attached to the rear surface of the door cover; a fanassembly for drawing out steam inside the tub, and mixing outside airand steam passing through the condenser; an outside air guide disposedin one side of the fan assembly to supply the outside air; and adischarge duct disposed in another side of the fan assembly to dischargea mixed fluid of the steam and the outside air to the outside.

According to a further aspect of the present invention, there isprovided a dishwasher including a tub defining a space where items arereceived; a door liner rotatably connected to a front side of the tub; afan assembly provided in a front side of the door liner to dischargesteam inside the tub, a condenser connected to the fan assembly, thecondenser including an inlet through which the discharged steam isintroduced, and an outlet through which the steam introduced into theinlet is again discharged and introduced into the fan assembly; adischarge duct connected to one side of the fan assembly; and an outsideair guide connected to another side of the fan assembly.

According to embodiments of the present invention, the steam dischargedduring the dry cycle can be rapidly condensed.

Also, the drying time can be shortened because the steam dischargedduring the drying cycle is rapidly cooled.

The user does not feel uncomfortable because the steam discharged duringthe drying cycle is rapidly cooled.

In addition, scalds associated with steam discharge can be eliminatedbecause the steam discharged during the drying cycle is rapidly cooled.

Further, an additional condenser is not required because a portion ofthe door may perform a function of the condenser.

Furthermore, condensation may not occur near the steam outlet and thuscondensed water is not discharged into an area surrounding thedishwasher, such as the floor. Therefore, it is possible to preventcondensed water from forming on floor space adjacent to the dishwasher,and consequently, prevent resulting accidents.

Moreover, it is possible to prevent mildew from forming at a corner dueto the condensed water falling down to the floor.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory, andshould not be construed as limiting the scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application. The drawings illustrate embodiment(s) of theinvention and together with the description serve to explain principlesof the invention. In the drawings:

FIG. 1 is a side sectional view of a dishwasher according to anembodiment of the present invention;

FIG. 2 is an enlarged view of a portion A of FIG. 1;

FIG. 3 is a front view of a door liner of a dishwasher according to anembodiment of the present invention;

FIG. 4 is a front view illustrating an exemplary condensation process ofthe dishwasher according to an embodiment of the present invention; and

FIG. 5 is a graph of the condensation process of FIG. 4.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to the various embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 is a side sectional view of a dishwasher according to anembodiment of the present invention, and FIG. 2 is an enlarged view of aportion A of FIG. 1.

Referring to FIGS. 1 and 2, the dishwasher 100 includes a cabinet 101defining an outer frame 102, a tub 110 protected by the cabinet andforming a washing chamber, a door 270 rotatably mounted at a front sideof the tub 110 to open/close the washing chamber, and a sump 170disposed at a bottom center portion of the tub 110 to contain washliquid.

The dishwasher 100 includes a washing pump 180 installed inside the sump170 to pump wash liquid under high pressure, and a motor 190 connectedto a shaft of the washing pump 180 to drive the washing pump 180.

The door 270 includes a door cover 272 and a door liner 271. The doorcover 272 defines a front appearance or exterior portion of thedishwasher. The door liner 271 is connected to a rear side of the doorcover 272. A condenser is interposed between the door cover 272 and thedoor liner 271, which will be described later.

The washing pump 180 may be controlled to stop its operation when anopening of the door 270 is detected during a high-temperature washcycle. Also, the washing pump 180 may be controlled to restart itsoperation after a predetermined time elapses when a closing of the door270 is detected.

The dishwasher 100 includes a water guide 140, a bottom nozzle 160, amiddle nozzle 150, and a top nozzle 155. The water guide 140 provides apath through which wash liquid pumped by the washing pump 180 flows. Thebottom nozzle 160 is disposed on the bottom of the tub 110 above thesump 170. The bottom nozzle 160 is configured to spray wash liquidupwards. The middle nozzle 150 is branched from a predetermined portion151 of the water guide 140 and is disposed near a center portion of thetub 110. The top nozzle 155 is disposed near a ceiling of the tub 110 tospray wash liquid vertically downwards. Each of the nozzles areconfigured to spray washing liquid toward items in racks.

The condenser 200 is disposed between the door cover 272 and the doorliner 271. A fan assembly is connected to an upper portion of thecondenser 200 to suck or draw out steam from within the tub 110.Specifically, the fan assembly includes a fan 260 for drawing out orsucking out steam from within the tub 110 and discharging steam to thecondenser 200. The fan assembly further includes a fan housing 250 forreceiving and housing the fan 260. A discharge duct 290 is connected toanother side of the fan housing 250 so as to discharge steam.

The condenser 200 is tightly attached to a rear side or interior side ofthe door cover 272, so that outside air and steam inside the condenser200 are heat-exchanged with each other through the door cover 272. Thatis, air outside the door 270 and steam inside the condenser 200 areheat-exchanged with each other by heat conduction through walls of thedoor cover 272 and the condenser 200. A front side of the condenser 200may be opened. The opened front side of the condenser 200 may be coveredand tightly sealed by the door cover 272, such that heat is achievedrapidly. That is, the door cover 272 may form a portion of the condenser200.

Specifically, the front side of the door cover 272 forms an exteriorportion of the dishwasher. The front side of the door cover 272 isexposed to the outside. The rear surface of the door cover 272 istightly contacted with the front surface of the condenser 200. The rearsurface of the door cover 272 may be exposed to high-temperature steamflowing through the condenser 200. Therefore, high-temperature steaminside the condenser 200 is condensed through heat exchange through thedoor cover 272 with external air, which may be air of room-temperature.

Since the door cover 272 of the door 270 is tightly contacted with oneside of the condenser 200 or forms a portion of the condenser 200,additional condensation components are not required, and thus thecondenser structure can be simplified.

Although the condenser 200 is provided inside the door as illustrated inthis embodiment, this configuration is only for exemplary purposes. Asanother option, the condenser 200 may be attached to a side of thecabinet 101 or may be formed as one component of the condenser 200. Inthis case, the condenser 200 is installed between the cabinet 101 andthe tub 110.

An operation of the dishwasher 100 illustrated in FIG. 1 will bedescribed below.

The user opens the door 270 of the dishwasher 100 and pulls an upperrack 120 and/or a lower rack 130 out of the washing chamber. The userplaces items, such as dishes, on the upper and/or lower racks 120 and130. Then, the user closes the door 270 and operates the dishwasher 100by switching it on.

When the dishwasher 100 performs a wash cycle, wash liquid is suppliedto the sump 170. After the supply of the wash liquid is completed, themotor 190 begins to operate. As an impeller of the motor 190 isrotating, the wash liquid is alternately pumped to the bottom nozzle 160or the water guide 140. The bottom nozzle 160 is configured to spraywashing liquid when it is pumped to the bottom nozzle 160 and ready tobe released. The impeller of the motor 190 is provided inside thewashing pump 180 connected to the shaft of the motor 190.

The wash liquid pumped to the water guide 140 flows to the top nozzle155 and the middle nozzle 150 and is sprayed into the washing chamber.Any items in the upper and/or lower racks 120 and 130 are washed by thesprayed wash liquid.

However, when the door 270 is opened during a high-temperature washcycle, the washing pump 180 restarts its operation after a predeterminedtime elapses so as to prevent the wash liquid contained in the sump 170from overflowing due to the expansion of cold air introduced into thetub 110.

In other words, when the sprayed high-temperature wash liquid comes incontact with low-temperature air, the wash liquid contained in the sump170 overflows due to air expansion. In order to prevent this phenomenon,the washing pump 180 is configured to stop its operation upon detectingan opening/closing of the door 270 or any such motion during thehigh-temperature wash cycle. Then, the washing pump 180 restarts itsoperation after a predetermined time elapses.

The top nozzle 155 is configured to spray the wash liquid verticallydownwards and the middle nozzle 150 sprays the wash liquid verticallyupwards, so that the dishes received in the upper rack 120 are washed bythe wash liquid from the top and middle nozzles.

In addition, the bottom nozzle 160 is configured to spray the washliquid vertically upwards, so that the dishes received in the lower rack130 are washed. Spray holes can also be formed at the bottom of themiddle nozzle 150. In this case, because the middle nozzle 150 spraysthe wash liquid upwards and downwards, the upper surfaces of the dishesreceived in the lower rack 130 can also be washed, while the lowersurfaces of the dishes received in the upper rack 120 are washed.

The dirty wash liquid collected in the sump 170 during the wash cycle isfiltered by a filter (not shown). When the dishwasher 100 finishes thewash cycle and begins a discharge cycle, a discharge pump (not shown)pumps the filtered wash liquid out of the dishwasher 100.

After the wash liquid is discharged, the dishwasher 100 is configured toperform a rinse cycle. That is, clean wash liquid is supplied to thesump 170 through an inlet and is sprayed through the nozzles 150 and 160similarly to the spraying of wash liquid provided in the wash cycle, sothat the dishes are rinsed by the sprayed clean wash liquid.

After the rinse cycle, the dishwasher 100 performs a drying cycle to drythe dishes and then the aforementioned dishwashing operation isfinished.

FIG. 3 is a front view of a door liner of a dishwasher according to anembodiment of the present invention, and FIG. 4 is a front viewillustrating a condensation process of the dishwasher according to theembodiment of the present invention.

Referring to FIGS. 3 and 4, a fan assembly, a condenser 200, and anoutside air guide 280 are provided in the front of a door liner 271forming a rear surface of the door. The fan assembly sucks or draws outsteam from inside the tub 110. A condenser 200 is connected to one sideof the fan assembly to condense the sucked or drawn steam. The externalair guide 280 is connected to another side of the fan assembly such thatair that is external to the tub is drawn in and provided to the fanassembly.

The fan assembly includes a fan 260 for sucking or drawing out the steamand discharging the steam, and a fan housing 250 for receiving andhousing the fan 260.

A hole is formed in the rear surface of the fan housing 250, and a holeis formed in the door liner 271. The hole of the door liner 271 issubstantially the same size as the hole of the fan housing 250. Theposition of the hole of the door liner 271 may correspond to theposition of the hole of the fan housing 250. A blower cover, which willbe described later, may be installed in the holes. An actuator, whichwill be described later, moves the blower cover forward and backward toselectively open/close the holes.

A steam outlet 252 is formed in a portion of a front surface of the fanhousing 250, and an outside air inlet 251 is formed in another portionof the fan housing 250. In addition, a mixed gas outlet 254 is formed inyet another portion of the fan housing 250. The condensed steam and theoutside air sucked through the outside air guide 280 are dischargedthrough the discharge duct into, for example, an indoor space.

Specifically, the condenser 200 includes an inlet through which thesteam is introduced, and an outlet through which the condensed steam isdischarged. At least one flow guide 201 is formed inside the condenser200 to guide a downward flow of the steam. A discharge hole 203 isformed at the bottom or lowermost portion of the condenser 200. Inaddition, a discharge hole, corresponding to the discharge hole 203, isformed in the door liner 271.

The steam outlet 252 is connected to the inlet of the condenser 200 andthe mixed gas outlet 254 is connected to the outlet of the condenser200. The discharge duct 290 extends down the door 270 and has adischarge opening 291 whose cross section is wider at the end of thedischarge duct 290 than at an upper portion of the discharge duct 290.An outside air inlet 281 is formed at the end of the outside air guide280 and is located under the door, such that the indoor air isintroduced through the outside air inlet 281.

During a drying cycle, the fan 260 received in the fan housing 250rotates and the blower cover is withdrawn, so that the holes of the doorliner 271 and the fan housing 250 are opened. Therefore,high-temperature, high-humidity steam existing inside the tub 110 isintroduced through the holes into the fan housing 250. The introducedsteam is discharged from the steam outlet 252 into the condenser 200.

In addition, the steam introduced through the inlet of the condenser 200descends along the flow guide 201. The descending steam in the condenser200 is cooled by the heat conduction with external air. External air mayrefer to air outside the tub or air outside the dishwasher. Condensedwater in the steam descending along the flow guide 201 is concentratedin the discharge hole 203 and is again introduced into the tub 110. Onthe other hand, steam that becomes gaseous after the condensation isconfigured to ascend along flow guide 202 and is introduced through amixed gas inlet 253 into the fan housing 250.

Simultaneously, indoor air is sucked or drawn in via an external airinlet 281 and passes through the outside air guide 280 to the outsideair inlet 251 of the fan assembly. External air may refer to air outsidethe dishwasher. Air drawn from outside the dishwasher may be air drawnfrom an indoor environment, such as air in a home or building. Theexternal air discharged to the outside air inlet 251 is introduced intothe fan housing 250 and is mixed with the steam discharged from themixed gas inlet 253. The mixture of the steam and the indoor air isagain condensed while descending along the discharge duct 290. That is,the mixed gas is condensed primarily in the condenser 200 andsecondarily in the discharge duct 290.

Meanwhile, the pressure of the mixed gas descending along the dischargeduct 290 is decreased while the mixed gas passes through the dischargeopening 291. In other words, the pressure of the gas decreases as thecross sectional area of the discharge opening 291 increases into anexpanding shape. As a result, the mixture or gas discharged through thedischarge opening 291 maintains a gaseous state throughout the dischargeduct 290. Thus, the condensation phenomenon does not occur around thedischarge opening 291.

It is preferable that the fan assembly includes a double-suctioncentrifugal fan because the fan 260 must suck or draw out steam fromwithin the tub 110 and external air through the outside air guide 280.

In addition, it is preferable that the air introduced through the flowguide 201 into the condenser 200 is sufficiently condensed. Therefore,it is preferable that the flow formed by the flow guide 201 is formed ina curved shape. For example, the flow guide 201 may include asubstantially S-shape or form.

Although the steam inside the tub and the indoor air are mixed in theinside of the fan housing 250, they can also be mixed in an area outsideof the fan housing 250.

FIG. 5 is a graph of an exemplary condensation process in accordancewith an embodiment of the present invention.

Referring to FIG. 5, reference numeral 300 represents a state in whichthe steam inside the tub is introduced into the condenser 200 via thesteam outlet 252. (See FIG. 4)

Specifically, the steam introduced into the condenser 200 reaches a dewpoint and is condensed into condensed water, while flowing through aflow path formed inside the condenser 200, as indicated by a referencenumeral 301. A reference numeral 302 represents a state in whichuncondensed steam arrives near the mixed gas inlet 253. As illustratedin FIG. 5, although a large amount of the high-temperature steam hasbeen condensed in the condenser 200, some steam still remains in a statesubstantially near the dew point.

Therefore, the remaining steam is mixed with the external air, which maybe indoor air at room temperature. In other words, external air existingin the state indicated by a reference numeral 303 is sucked in throughthe outside air guide 280 and discharged to the condenser 200. Then, theoutside air is mixed with the steam 302 and introduced into the fanhousing 250. The mixed gas reaches a state indicated by reference number304. That is, the mixed gas reaches a state substantially below the dewpoint. Therefore, although the mixed gas is discharged from thedischarge opening 291, dew condensation around the discharge opening 291can be minimized. In addition, the mixture or gas discharged from thedischarge opening 291 is able to maintain its gaseous state via theexpanding shape of the discharge opening 291.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the invention. Thus, it is intended that the claimscover the modifications and variations provided they come within thescope of the claims and their equivalents.

1. A dishwasher comprising: a tub defining a washing chamber; a door foropening/closing the tub; a condenser provided within the door tocondense steam discharged from the tub; a fan assembly connected to thecondenser, the fan assembly including a steam outlet through which steaminside the tub is discharged into the condenser; and an air guide forsupplying air external to the tub to the fan assembly.
 2. The dishwasheraccording to claim 1, wherein the door comprises a door liner exposed toan interior of the tub, and a door cover, provided at a front side ofthe door liner, to form an exterior portion of the dishwasher, whereinthe condenser is disposed between the door liner and the door cover. 3.The dishwasher according to claim 2, wherein the condenser is sealed toa surface of the door cover.
 4. The dishwasher according to claim 2,wherein a front side of the condenser is opened, the opened front sidebeing closed by the door cover and being sealed to the door cover. 5.The dishwasher according to claim 2, wherein steam introduced into thecondenser is heat-exchanged with the external air by heat conductionthrough the door cover.
 6. The dishwasher according to claim 1, furthercomprising a discharge duct provided at another side of the fan assemblyto discharge a mixture of the external air and the steam.
 7. Thedishwasher according to claim 6, wherein the steam discharged throughthe discharge outlet is configured to be condensed primarily in thecondenser and configured to be condensed secondarily while passingthrough the discharge duct.
 8. The dishwasher according to claim 6,wherein the discharge duct has an outlet having an expanding shape.
 9. Adishwasher comprising: a tub; a door for opening/closing a front side ofthe tub, the door including a door cover defining an exterior portion ofthe dishwasher and a door liner connected to a rear surface of the doorcover; a condenser attached to the rear surface of the door cover; a fanassembly to draw out steam from inside the tub and discharge the steamto the condenser, the fan assembly further mixing air external to thetub with steam passing through the condenser; an air guide disposed atone side of the fan assembly to supply the external air; and a dischargeduct disposed at another side of the fan assembly to discharge a mixtureof the steam and external air.
 10. The dishwasher according to claim 9,wherein the fan assembly comprises: a fan housing; a fan housed in thefan housing; and a blower cover provided at a side of the fan housing toprovide selective communication between the tub and the fan housing. 11.The dishwasher according to claim 10, wherein the fan housing comprisesa discharge hole through which the steam inside the tub is discharged,the discharge hole being connected to an inlet of the condenser.
 12. Thedishwasher according to claim 10, wherein the condenser comprises anoutlet through which condensed steam is discharged, the outlet beingconnected to the fan housing.
 13. The dishwasher according to claim 10,wherein the fan comprises a double-suction centrifugal fan.
 14. Thedishwasher according to claim 9, further comprising at least one flowguide provided inside the condenser to guide a flow of the steam. 15.The dishwasher according to claim 9, further comprising at least onehole formed in a lower portion of the condenser and the door liner suchthat water formed from the condensed steam is introduced into the tub.16. The dishwasher according to claim 15, wherein the lower portion ofthe condenser slopes downward.
 17. The dishwasher according to claim 9,wherein the outside air guide comprises an opening exposed to externalair.
 18. A dishwasher comprising: a tub defining a washing space; a doorliner rotatably connected to a front side of the tub; a fan assemblyprovided at a side of the door liner to discharge steam from within thetub; a condenser connected to the fan assembly, the condenser includingan inlet through which the discharged steam is introduced into thecondenser, and an outlet through which the steam from the condenser isagain discharged and introduced into the fan assembly; a discharge ductconnected to at least one side of the fan assembly; and an outside airguide connected to another side of the fan assembly.
 19. The dishwasheraccording to claim 18, wherein the steam introduced into the inlet isconfigured to be condensed primarily in the condenser and steam from thecondenser is discharged to the fan assembly.
 20. The dishwasheraccording to claim 19, wherein the primarily condensed steam is mixedwith external air drawn into the outside air guide and is configured tobe condensed secondarily through the discharge duct.
 21. The dishwasheraccording to claim 18, wherein the condenser comprises: a flow guidesloping downwards such that the steam discharged from the tub iscondensed while moving along a curved flow path; and a water hole formedat a lower edge of the condenser to introduce the condensed water intothe tub.
 22. The dishwasher according to claim 18, wherein a crosssectional area of the outlet of the discharge duct is wider than a crosssectional area of the inlet of the discharge duct.
 23. The dishwasheraccording to claim 18, wherein the fan assembly comprises adouble-suction centrifugal fan.